Homework 1 - lab answers

STA 101L - Summer I 2022

Raphael Morsomme

Setup

You can find the lab here.

library(tidyverse)
library(openintro)

Exercise 1 (2 points)

arbuthnot$girls

 [1] 4683 4457 4102 4590 4839 4820 4928 4605 4457 4952 4784 5332 5200 4910 4617
[16] 3997 3919 3395 3536 3181 2746 2722 2840 2908 2959 3179 3349 3382 3289 3013
[31] 2781 3247 4107 4803 4881 5681 4858 4319 5322 5560 5829 5719 6061 6120 5822
[46] 5738 5717 5847 6203 6033 6041 6299 6533 6744 7158 7127 7246 7119 7214 7101
[61] 7167 7302 7392 7316 7483 6647 6713 7229 7767 7626 7452 7061 7514 7656 7683
[76] 5738 7779 7417 7687 7623 7380 7288

Exercise 2 (3 points)

arbuthnot %>%
  ggplot(aes(x = year, y = girls)) +
  geom_point() +
  geom_line()

arbuthnot %>%
  ggplot() +
  geom_line(aes(x = year, y = girls))

Exercise 3 (4 points)

arbuthnot %>%
  mutate(prop_boys = boys / (boys + girls)) %>%
  ggplot() +
  geom_line(aes(year, prop_boys))

Exercise 4 (4 points)

present

# A tibble: 63 x 3
    year    boys   girls
   <dbl>   <dbl>   <dbl>
 1  1940 1211684 1148715
 2  1941 1289734 1223693
 3  1942 1444365 1364631
 4  1943 1508959 1427901
 5  1944 1435301 1359499
 6  1945 1404587 1330869
 7  1946 1691220 1597452
 8  1947 1899876 1800064
 9  1948 1813852 1721216
10  1949 1826352 1733177
# ... with 53 more rows

present$year

 [1] 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954
[16] 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
[31] 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
[46] 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
[61] 2000 2001 2002

min(present$year)

[1] 1940

max(present$year)

[1] 2002

nrow(present)

[1] 63

ncol(present)

[1] 3

dim(present)

[1] 63  3

present

# A tibble: 63 x 3
    year    boys   girls
   <dbl>   <dbl>   <dbl>
 1  1940 1211684 1148715
 2  1941 1289734 1223693
 3  1942 1444365 1364631
 4  1943 1508959 1427901
 5  1944 1435301 1359499
 6  1945 1404587 1330869
 7  1946 1691220 1597452
 8  1947 1899876 1800064
 9  1948 1813852 1721216
10  1949 1826352 1733177
# ... with 53 more rows

Exercise 5 (2 points)

# Insert code for Exercise 5 here

Exercise 6 (5 points)

present %>%
  mutate(prop_boys = boys / (boys + girls)) %>%
  ggplot() +
  geom_line(aes(year, prop_boys))

Exercise 7 (5 points)

present %>%
  mutate(total = boys + girls) %>%
  arrange(desc(total))

# A tibble: 63 x 4
    year    boys   girls   total
   <dbl>   <dbl>   <dbl>   <dbl>
 1  1961 2186274 2082052 4268326
 2  1960 2179708 2078142 4257850
 3  1957 2179960 2074824 4254784
 4  1959 2173638 2071158 4244796
 5  1958 2152546 2051266 4203812
 6  1962 2132466 2034896 4167362
 7  1956 2133588 2029502 4163090
 8  1990 2129495 2028717 4158212
 9  1991 2101518 2009389 4110907
10  1963 2101632 1996388 4098020
# ... with 53 more rows